“The way the Boston Strangler movie has been described in the press is eerily familiar,” Sherman told the Track. “It could have been lifted off the back cover of my book.”

Sherman, who undertook a 10-year investigation into the Boston Strangler killings, believes he has a chokehold on the facts of the case. His aunt, Mary Sullivan, was purportedly the Strangler’s last victim.

Sherman proved via DNA evidence that Albert DeSalvo, who confessed to 13 Strangler murders including Sullivan’s, was not her killer and cast serious doubt on the validity of the former handyman’s confession to all of the slayings.

Sherman concludes that the Strangler murders were not the work of a single serial killer but a number of killers and copycats but that investigators, desperate for a conviction, pinned them on DeSalvo to appease the panicked public.

A few weeks ago, Sherman said, his agent got an email from a rep at Langley Park Productions, a division of Warner Brothers, inquiring whether the movie rights to the book were available.

The author said his agent replied saying they were available but never heard anything else.

Last week, Deadline.com reported that Warner Brothers had acquired “Boston Strangler,” about “the desperate search for the murderer who terrorized the Boston area during the early 1960s” from Affleck and Quincy screenwriter Chuck MacLean.

Langley Park would produce, according to the report, with Affleck attached to executive-produce and star as a detective “willing to risk career and life in a race to bring down the most notorious sexual predator of the day, while battling a political cover-up by corrupt politicians and lawyers trying to save their careers.”

The script would be written by MacLean, whose “Bridges on the Fort Point Channel” about Boston’s busing crisis was voted one of the best unproduced scripts of 2011 by Hollywood film execs.

Sherman said the announcement left him feeling “very used.” He said he believes Langley Park inquired about the rights to his book in order to determine whether there were any competing projects in the works.

“And all of a sudden Casey Affleck is attached to a Boston Strangler movie,” Sherman said.

“The only Casey who should be attached to that movie is the Casey who actually re-investigated the crimes.”

The Langley Park peeps did not return our emails and calls for comment. Ditto for Affleck’s publicist.